Circular Locking Dependency in Linux Kernel's Cgroup Functionality

CVE-2023-53522

What is CVE-2023-53522?

A vulnerability exists in the Linux kernel related to a circular locking dependency between the cpu_hotplug_lock and freezer_mutex. This issue arose from a revision of the core freezer logic, where the atomic increment operation was replaced with a static branch increment in the freezer_apply_state function. The modification introduced complexities in the locking mechanisms, which could lead to deadlocks in systems utilizing cgroups. To mitigate this issue, the correct locking order is crucial, necessitating a change that moves the cpus_read_lock before the freezer_mutex lock in the freezer_change_state function.

References